This program is an implementation of a real problem: search the courses and the students that constitutes a circle and find all circles.

在文件qiexian.m中输入两个摩尔圆的坐标即可画出莫尔圆，并求出两圆的切线(In the file qiexian.m, enter the moire circle with the coordinates of two Moore circles, you can find the tangent of the two circle.)